1. Field of the Invention
The present invention relates to a bellows which can be advantageously used in an optical instrument, such as a camera, or various kind of machine tools or which can be used as a passageway.
2. Description of the Related Art
A bellows in a camera is usually made of a flexible tubular body bent in alternate directions along folds spaced at predetermined distances along the length thereof so as to provide extensibility and retractility. Between the folds, reinforcements are provided on the tubular body to prevent the latter from easy deformation.
The sheet by which the tubular body is made is usually composed of three superimposed layers. The reinforcements are usually provided on the innermost layer. The reinforcements consist of paper or the like precut into strips of a predetermined shape. These strips are adhered to the innermost layer of the tubular body, for example, by means of paste. In particular, when the strips are irregular in shape, or improperly positioned by the paste, there is a decrease in the collapsibility, one of the most significant properties of a bellows, and the durability.
Accordingly, it is very important to precut the reinforcing paper into strips of a predetermined shape and adhere them to the innermost layer of the sheet with a high precision. These precut and adhesion operations must therefore be effected manually by a highly skilled person. It is, however, difficult to uniformly cut and adhere the strips with a high precision by a mass-production process.